Drones help farmers weed out crop disease

Agricultural researchers are experimenting with the use of
drones to monitor the growth of crops.

Dennis Bowman, a crop scientists at the University of Illinois, is using two drones -- a
remote-controlled Phantom quadcopter and a Parrot AR Drone with GPS
-- to take aerial shots of fields to see which areas may need more
attention.

In carrying out the research, Bowman purposefully made mistakes
with the application of fertiliser in order to see whether the
drones could pick up on problems before people on the ground. This
may offer farmers more time to act -- either through replanting an
area or adding fertiliser -- in order to optimise the crop. The aim
is to also use the drones to monitor the impact of herbicides that
are applied after a pest outbreak is detected.

Conventionally farmers hire "crop scouts" to walk through fields
of corn and other plants to check their condition. Bowman says he
spent two summers doing this and it "is not a pleasant task" in the
heat. "The odds of actually getting to the far end of that field on
foot to see what's going on are pretty slim. To get a bird's-eye
view of your crop, the drones offer a handy way to do it."

The drones use rechargeable batteries and make flights of up to
15 minutes. The drones have been equipped with a gimbal and GoPro
and have a flight control system so that they can follow a
prescribed route using GPS.

"Standard pictures and video can tell us a lot," says Bowman,
but the next step is to use multispectral cameras that offer images
in other wavelengths, such as near-infrared, which can identify
crop stress -- plants that absorb or reflect light differently may
be experiencing nutrient deficiency, pest problems or disease. "It
probably isn't going to tell us what the problem is, but it will
tell us where problems are so that we can target our scouting in
those specific areas and determine what might be occurring."

Bowman is already using a Canon Powershot SX260 with an upgraded
lens that can carry out infrared photography. One specific problem
that this can help with is identifying the spread of invasive and
herbicide-resistant weed Palmer amaranth. The weeds offer up a
different spectrum response from crops like soybeans and so they
can be easy to identify from above.

The US Federal Aviation Administration has banned the commercial
use of unmanned aerial vehicles, but is under increasing pressure
to update its policies to allow for the use of drones. The
agriculture industry is likely to be a significant market.

If the FAA does update its rules (which is expected in 2015),
Bowman predicts that "in the future a farmer will get up in the
morning, hit a button and launch a couple of drones that fly out
over his farms and collect imagery that's sent wirelessly to his
office".